/*
 * Copyright (c) 2007, 2021, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.sun.org.apache.xml.internal.utils;

import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;

/**
 * This class implements a generic PrefixResolver that
 * can be used to perform prefix-to-namespace lookup
 * for the XPath object.
 *
 * @xsl.usage general
 */
public class PrefixResolverDefault implements PrefixResolver {

    /**
     * The context to resolve the prefix from, if the context
     * is not given.
     */
    Node m_context;

    /**
     * Construct a PrefixResolverDefault object.
     *
     * @param xpathExpressionContext The context from
     *                               which XPath expression prefixes will be resolved.
     *                               Warning: This will not work correctly if xpathExpressionContext
     *                               is an attribute node.
     */
    public PrefixResolverDefault(Node xpathExpressionContext) {
        m_context = xpathExpressionContext;
    }

    /**
     * Given a namespace, get the corrisponding prefix.  This assumes that
     * the PrevixResolver hold's it's own namespace context, or is a namespace
     * context itself.
     *
     * @param prefix Prefix to resolve.
     * @return Namespace that prefix resolves to, or null if prefix
     * is not bound.
     */
    public String getNamespaceForPrefix(String prefix) {
        return getNamespaceForPrefix(prefix, m_context);
    }

    /**
     * Given a namespace, get the corrisponding prefix.
     * Warning: This will not work correctly if namespaceContext
     * is an attribute node.
     *
     * @param prefix           Prefix to resolve.
     * @param namespaceContext Node from which to start searching for a
     *                         xmlns attribute that binds a prefix to a namespace.
     * @return Namespace that prefix resolves to, or null if prefix
     * is not bound.
     */
    public String getNamespaceForPrefix(String prefix,
                                        org.w3c.dom.Node namespaceContext) {

        Node parent = namespaceContext;
        String namespace = null;

        if (prefix.equals("xml")) {
            namespace = Constants.S_XMLNAMESPACEURI;
        } else {
            int type;

            while ((null != parent) && (null == namespace)
                    && (((type = parent.getNodeType()) == Node.ELEMENT_NODE)
                    || (type == Node.ENTITY_REFERENCE_NODE))) {
                if (type == Node.ELEMENT_NODE) {
                    if (parent.getNodeName().indexOf(prefix + ":") == 0)
                        return parent.getNamespaceURI();
                    NamedNodeMap nnm = parent.getAttributes();

                    for (int i = 0; i < nnm.getLength(); i++) {
                        Node attr = nnm.item(i);
                        String aname = attr.getNodeName();
                        boolean isPrefix = aname.startsWith("xmlns:");

                        if (isPrefix || aname.equals("xmlns")) {
                            int index = aname.indexOf(':');
                            String p = isPrefix ? aname.substring(index + 1) : "";

                            if (p.equals(prefix)) {
                                namespace = attr.getNodeValue();

                                break;
                            }
                        }
                    }
                }

                parent = parent.getParentNode();
            }
        }

        return namespace;
    }

    /**
     * Return the base identifier.
     *
     * @return null
     */
    public String getBaseIdentifier() {
        return null;
    }

    /**
     * @see PrefixResolver#handlesNullPrefixes()
     */
    public boolean handlesNullPrefixes() {
        return false;
    }

}
